RGB到BMP图像转换函数

int CDMATestDlg::bmp_write(unsigned char *image, int xsize, int ysize, char *filename)
{
unsigned char header[54] = {
0x42, 0x4d, 0, 0, 0, 0, 0, 0, 0, 0,
54, 0, 0, 0, 40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 24, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0
    };
    
    long file_size = (long)xsize * (long)ysize * 3 + 54;
    header[2] = (unsigned char)(file_size &0x000000ff);
    header[3] = (file_size >> 8) & 0x000000ff;
    header[4] = (file_size >> 16) & 0x000000ff;
    header[5] = (file_size >> 24) & 0x000000ff;
    
    long width = xsize;
    header[18] = width & 0x000000ff;
    header[19] = (width >> 8) &0x000000ff;
    header[20] = (width >> 16) &0x000000ff;
    header[21] = (width >> 24) &0x000000ff;
    
    long height = ysize;
    header[22] = height &0x000000ff;
    header[23] = (height >> 8) &0x000000ff;
    header[24] = (height >> 16) &0x000000ff;
    header[25] = (height >> 24) &0x000000ff;

    char fname_bmp[128];
    sprintf(fname_bmp, "%s.bmp", filename);